You got wrong the metric system and the name of the smallest unit. From the wiki:

There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:

    1 BTC = 1 bitcoin
    0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)
    0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)
    0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)

One exception is the "satoshi" which is smallest denomination currently possible

    0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)